Reciprocating piston engine type gas generator for gas turbines



May 31, 1960 Original Filed Feb. 18, 1948 A. BUCHI RBCIPROCATING PISTON ENGINE TYPE GAS GENERATOR FOR GAS TURBINES 7 Sheets- Sheet 1 Alfml BUCH\ INVENTOR WW, z-WZ v P May 31, 1960 A. BUCHI 2,938,506

RECIPROCATING PISTON ENGINE TYPE GAS GENERATOR FOR GAS TURBINES Original Filed Feb. 18, 1948 7 Sheets-Sheet 2 40' 29' so 30 29, 4o

1 AIM 50cm INVENTOR May 31, 1960 A. BUCHI 2,938,506

RECIPROCATING PISTON ENGINE TYPE GAS GENERATOR FOR GAS TURBINES Original Filed Feb. 18, 1948 7 Sheets-Sheet 3 9 AIM Bucm INVENTOR JIM/ Pm/QL May 31, 1950 A. BUCHl 2,938,506

RECIPROCATING PISTON ENGINE TYPE GAS GENERATOR FOR GAS TURBINES Original Filed Feb. 18, 1948 '7 Sheets-Sheet 4 Ahmfl BUCHI INVENTOR v A'H's May 31, 1960 A BUCHI 2,938,506

RECIPROCATING P ISTON ENGINE TYPE GAS GENERATOR FOR GAS TURBINES Original Filed Feb. 18. 1948 7 Sheets-Sheet 5 Alfmfi. SUCH! INVENTOR B wlihi imbfmi A. BUC CATING PIS NERATOR FO May 31, 1960 PE GAS S 7 Sheets- Sheet 6 HI TON ENGINE TY R GAS TURBINE RECIPRO GE Original Filed Feb. 18. 1948 QMWIMMM MU Hm hhwhlw 9:1!

Ami BUCHI V INVENTOR WM, Z Afis May 31, 1960 A. BU'CHI 2,938,506

RECIPROCATING PISTON ENGINE TYPE GAS GENERATOR FOR GAS TURBINES Original Filed Feb. 1a, 1948 7 Sheets- Sheet 7 U a; nu NMWAU 1! m n IL WW null u Al DA @6 wm m M l H \mm L D 2 a D. 2 P c K b fi B D D. u u D a M a L m D M M 2 I llllll C M lllllwfiql D (m u D BUCHI B I NVE NToR WM! United States PatentO RECIPROCATING PISTON ENGINE TYPE GAS GENERATOR FOR GAS TURB v Alfred Buchi, Winterthur, Switzerland; Dr. Hermann Walder, executor of the said Alfred Buchi, deceased Claims priority, application Switzerland Feb. 19, 1947 18 Claims. (Cl. 123 -52 This application is a division of my co-pending application Serial No. 369,848, filed July 23,1953, in turn a division of 9,284, filed February 18, 1948, both now abandoned.

The invention relates to gas generators in the form of supercharged four-cycle reciprocating piston types of internal combustion engines feeding a pressure medium to a gas turbine delivering useful work. It consists specifically in a novel way of equipping the piston engine, on one hand, with charging medium pumps acting simultaneously as crosshead guides, for delivering charging air during the inlet period of the internal combustion engine, and on the other hand with piston pumps driven by the engine crankshaft which compress air beyond the pressure of the charging air, so that additional (secondary) air of higher pressure is fed via the internal combustion engine mainly during its exhaust period and through to the gas turbine. The charging air pump may be built single-acting or double-acting. In the latter case the lower side of the piston may act as a dilferential piston to permit the inner piston guide of smaller diameter to serve as crosshead guide. The engine-crankshaft-driven pump for the secondary air may be built as a doubleacting air pump with at least two cylinders arranged in tandem, having approximately the same structural height as the internal combustion engine, with correspondingly short piston stroke. The secondary air pump may be driven from the extension of the engine crankshaft, i.e. on one or both ends of the latter. I r

The arrangement may be so that the cranks of the secondary pump cylinders are set out of phase to the cranks of the corresponding internal combustion engine cylinders, operating regarded to the latter. This is done preferably so, with corresponding timing of exhaust and air controlling gear, that first during an appreciable part of the exhaust periods of the engine cylinders only uncooled, hot exhaust gases flow from the engine cylinders to the gas turbine, and the cooler secondary air is introduced subsequently, first as cooling air, afterward as scavenging air during the period near the upper dead center position of the engine piston, for sweeping out the combustion gases from the engine cylinder. Subsequently, a further deliberate temperature reduction of the cylinder contents is accomplished through their expansion to the charging air pressure level prior to the actual admission stroke of the engine cylinders.

The internal combustion engine delivering the pressure medium may be fitted with multiple cylinder banks arranged side-by-side, and have double-acting piston compressors delivering secondary air drivingly connected on one or both ends of each cylinder bank, whereby the cylinders of said piston compressors may be grouped vertically in tandem. Furthermore, the crankshafts of the cylinder banks with internal combustion cylinders and compressor cylinders may be so coupled by means of gear wheels that the irregularities of torque and inertia forces and moments in the cylinder banks largely compensate each other. Suitable intermediary gear wheels may be so arranged between the crankshafts that the crankshafts of two adjacent cylinder banks have opposite sense of rotation and that the cranks or" those internal combustion cylinders which are located in about the same transverse plane to the crankshaft are so set that said cylinders have simultaneous timing of their respective work phases (compression, combustion, expansion, etc.). Thus, the crosshead pressures acting transversely to the piston axis compensate each other with regard to the engine frame.

According to this invention, at least two cylinder banks drivingly connected with charging air pumps may also be arranged in V-form, and all the cylinders may drive a common crankshaft by means of connecting rods.

The charging air pumps which are driven by the combustion engine cylinders may deliver the charging air to at least one receiver arranged between said pumps and the engine cylinders and the charging air may be arranged to flow from said receiver or receivers to at least part of the engine inlet devices by common ducting.

At least one receiver for the secondary air may be located alongside the internal combustion cylinders. Between the receivers for the charging air and for the secondary air, suitable controlling means may be arranged which direct the charging air as well as the secondary air to the inlet devices or at least one engine cylinder at the proper time. For the control of the charging air as well as of the secondary air there may be arranged at least one similar common device each for two engine cylinders located adjacently in a transverse plane to the engine axis. Pistontype sleeve valves, for instance, may serve as controlling means for charging and secondary air. They may be guided by means of two coaxial guide surfaces of different diameters in such a man ner that despite the different pressure levels of charging air and secondary air there is approximate compensation of all pressures acting on said piston valve, with respect to the controlling forces for said piston valve.

In case of combustion engine cylinder banks arranged side-by-side, the admission of the charging air and of the secondary air may be effected by common ducts arranged between the banks, whereas the discharge of exhaust gases is effected by pipes arranged separately on the outside of the engine cylinder banks leading to the gas turbine. The charging air as well as the secondary air may, however, also be admitted from the outside of the engine cylinder banks, whereas the exhaust gases of the engine cylinders leave the latter through at least one exhaust manifold which is common for the cylinder banks and arranged between said banks in the middle of the engine. The exhaust pipes for the various engine cylinders may be combined in groups which are led separately to at least one turbine or to one turbine sector each so that the exhaust periods of any cylinders cannot disturb the exhaust periods and scavenging action in any other, cylinders. The embodiment according to this invention has the advantage of making a very compact and simple piston type combustion gas generator for gas turbines. A large part of the cylinder output is transmitted directly to the charging air pumps and to the other engine cylinders and the secondary air pumps. The piping for the charging and secondary air to the engine cylinders is very short, and its control very simple. The control forces for these air guiding devices are small, and

' the control devices may be built in form of piston sleeves.

compensate each other with respect to the engine frame.

The cranks of the cylinder banks may be so set thatrtheo moments of cylinder and inertia forces compensate each other.

T -a m s on Q sqq d r a r to e en ne cy inders may be arranged so that during a substantial part pfthe exhaust period first only hot,uncooled combustion gases are transmitted to the gas turbine. Subsequently, sec: sda r a rw y be ro u ed; as qol ns rduxi s he exhaust-stroke and-as scavenging air around the timeof the outer dead center positionof the respective engine piston. This scavenging air admission may be followed by an expansion of the engine cylinder charge to the lower'pressure level of the charging air, with correspond;

ing further temperature reduction of said charge, The secondary air pumps may be so coupled against the internal combustion'engine that maximum air delivery to the engine cylinders is accomplished. i

The engine cylinders may discharge their exhaust gases to one or more gas turbines. The respective exhaust gas conduits may be subdivided into groups. The in: ternal combustionengine may be so built that it drives directly at least part of its auxiliaries, such as fuel pumps, c in Water Pumps, ca The object of this invention and its functioning is illustrated in various examples in figures on 7 sheets. Same numbers or letters mean the same or similar parts or conditions.

; Big. 1 shows a, vertical transverse section through one cylinder of an injline type of internal combustion engine withone crankshaft working according to the invention. Fig. 2, showsfla similar section through a twin-bank? type of internal combustion engine having two cylinder banks andtwo, crankshafts.

Fig. 3 show,s partial vertical sections along the crankshaft axis-of the internal combustion engine, and partial side views of same.

Fig. 4 shows top views of a twin-crankshafttype of a sixteen-cylinder internal combustion engine. It contains also a horizontal section through the cylinder cover. region of fourengine cylinders.

Fig. S'showson the left a vertical section, and on the right a side view. with partial section through a secondary, air pump operating together'with the cylinders of the internal combustion engine.

Eigs. 6 and7 show top views of complete gas generator plants arrangedto'ge'ther with the gas turbine or turbines which deliver the useful work. Fig. '6 refers to a gas. turbine driving an electrical generator. Fig. 7 refers particularly'to apower plant for locomotive drive, where two gas Tt'urbines'drive through gears.

' Figs. 8, 9; and 10 show, in diagram form, the. controltiming sequence and approximate timing of engine cylinder pressures and temperatures, of the pressures in charging air pumps and in secondary air pumps, in function ofthe crank angle position of one piston of an internal combustion engine according to this invention.

In Fig. -1', 1 is a cylinder of a four-cycle internal combustion engine acting as gas generator. 2' is its single-' acting working piston, and 3 is its piston rod. According to the invention, the internal combustion engine operates with crosshead 4' which acts simultaneously as piston 5 of the charging air pump.' The latter could also be built as a double-acting differential piston whereby the lower piston guide serves as crosshe'ad. 6 is the engine crankshaft, and '7 the connecting rod of cylinder 1 whichltransmits the forces from pistons 1 and 5" to- 11 each are; arranged sa'id; control devices being actuated from 'the camshaft 12 by means of can-is 13, 13' and of I j a caress: P mp. a iases .5 he es-teaserthe control gear 14, 14'.

is drawn in by the piston 5' through'opening 16 and the suction valves 17 and pushed into a receiver 19 which is common for at least part of the internal combustion engine. The engine cylinders 1' as well as its cylinder covers 20' and the charging air pump cylinders 15' may be equipped with water-cooling, as shown. They could s. be airl a n ea According to this invention, at least'cne-piston type 19W? 1 a l ia s liaslsr s new u l t he ece Dintrgnt of the inlet control device 10. This sleeve controls the transmission of charging air from receiver 19 to inlet valve 10, and also controls the transmission of secondary air from the above-lying space 22 to said inlet valve 10. Thereby thepistonsleeve 21 is so shaped as to have an inner cylindrical guide 23 whose inner ms r i 9 howuand s ssa sd ai st sp e 22 th despite the higher pressure of the secondary air in space 22 as against the lower charging air pressure in the receiver 19 the piston sleeve 21, 23 is subjected to approigimately equal forces from abovewand below. For this purpose, a stationary guide 24 whose central cavity mayv for instance be connected with the atmosphere, is made to extend into the piston sleeve 21, 23 from above. On the'outer sleeve part 21 and on the inner sleeve part 23, piston rings 25 and 26 respectively may be builtin'. The'piston sleeves 21 may be actuated by cams as illustrated, e.g.. also from the camshaft 12 of the internal combustionengine. For this purpose, a cam and suitable operatinggear 27, 28 may be arranged there in wellknown. fashion.

. 32 is the. exhaust gas conduit to the gas turbine. In Fig. 2 which illustrates a vertical section throughan interiial. combustion engine with two cylinder banks arranged: side-by-side, the parts of different cylinder banksv which are identical or similar to each other are identified by high or low index on their respective numbers. .For instance, the engine cylinders are numbered 1' and 1 the. pistons 2' and 2 the piston rods 3 and 3 the cros'shead guides 4' and 4 the charging air com pressor pistons 5 and 5 and so on.

The receiver 19-is arranged between the two cylinder banks Thecharging air flows through the valves 18 and 181 into this receiver 19. When the piston sleeve valve 21-is opened, the charging air is led from the rec'eiv-er- 19 vup to the inlet'valve 10 and 10 The piston sleeve valve 21 is shown to be of similar designas the one on- Eig. 1. In Fig. 2, however, the chargirig air is led from below to the inlet valves 10 and 10 of the two cylindersl' and 1 bya common sleeve valve 21. This sleeve valve. 21 simultaneously controls, with its upper-'- edge, also the admission of the secondary air from the above-lying space-22 to the inlet valves 10 and 10 of both of said cylinders 1" and 1 T Thecrankshafts 6' and 6 may be coupled through gears, for instance by gear wheel pairs 29', 29 and 38', 3Q "I The two banks of'internal combustion cylinders rotate with the same speed, preferably in opposite direction which is accomplished by suitable gearing as shown in Fig.' 2. The cranks of two engine cylinders lying in approximately the same transverse plane to the crank shaft maybe so set that said two engine cylinders have simultaneous work'phases such as induction, compression, combustion, expansion, etc. The lateral pressures of thecross-'heads-4' and 4 of said engi'necylinders thus com-J s di as rs pensate each other with respectto the engine frame 8. Withl'such a de'si'gn horizontal inertia forces on the engine-frame are eliminated; This is very important 'es--' pecially for the installation of such an engine on a vehicle-.

auxiliaries sue-has cooling water pumps, electrical gen-l erators, fans, etc, may be driven advantageously-from the shafts of gear wheels 30 to 30 In this case, said shafts ar e pre ferablymade torotate at speeds higher than;

engine crankshaft speed, by suitable choice of their gear her 1;; sirwli his e i r r s' s ru i g and 15 into the receiver 19 may serve not only for charging the engine cylinders 1', 1 etc., but also for charging, is. to act as a first stage of the secondary air pump. If such secondary air pump is arranged at least on one front end of the internal combustion engine, the charging air may be transmitted from receiver 19 to the secondary air pump through openings 31 in the end face of the engine frame, so that all charging airpiping outside of the engine frame is eliminated.

In Fig. 3, on the right, is shown a section through cylinder 1', the piston 2 and the piston rod 3' of an engine cylinder. The fuel injection nozzle 53', shown here, centrally-located, and the charging air piston 5', its crosshead 4', the connecting rod 7 and the crankshaft 6 are also visible on this section. Beside the sectioned cylinder 1', there is a cylinder 1" on which a section through the secondary air conduit 22 as well as through piston sleeve valves 21, 21, is shown. Two sleeve valves 21 and 21 per cylinder, arranged side-by-side in a longitudinal plane through the engine, are shown here.

In case of an engine according to Fig. 2, each of the two piston sleeve valves may serve two engine cylinders l and 1 which are located in a plane approximately transversal to the crankshafts. Therefore, the two sleeve valves 21 and 21 serve two engine cylinders.

The piston sleeve valves 21 and 21' of cylinder 1" are drawn in a raised position so that the charging air can flow from the receiver 19 below to the inlet valves 10' and 10 which are not shown here. The piston sleeve valves 21 and 21' for the engine cylinder 1" are shown in a lower position whereby secondary air can flow downward from conduit 22 through guides 24 and 24' to the inlet valves 10 and 10 Fig. 4 shows a top view upon a twin bank gas generator engine with sixteen engine cylinders, arranged in two banks of eight cylinders each, with separate crankshafts for each bank. 1', 1", 1", 1", 1"', 1""", 1''", and 1"""" are the cylinders of one bank, and 1 i 1 1 1 1 1 and 1 are the cylinders of the other ank.

A secondary air pump 33 is built on the front end of the internal combustion engine. It consists of at least four cylinders, preferably double-acting, arranged sideby-side in pairs of two, and driven by the crankshaft of at least one engine cylinder bank. Some pump cylinders may also be arranged in tandem above each other. The secondary air pump cylinders obtain their admission air from the receiver 19 of the internal combustion engine through openings 31, as is illustrated in Fig. 2. They discharge the compressed air through conduit 22 to the piston sleeve valves 21 and 21'. The horizontal sections through the two cylinder covers 20"" -20 and 20"""" 20 respectively show the path of the charging air and secondary air through the piston sleeves 21 and 21' to the inlet valves 10 and 10 Dual inlet valves 10 and 10 and dual exhaust valves 11' and 11 per engine cylinders are used in this example. The exhaust valves 11' and 11 discharge the engine exhaust gases, in this instance, through two exhaust manifolds 32 and 32 to a gas turbine not shown here.

Fig. 5 shows by way of example an embodiment of the secondary air pump 33 on Fig. 4. The extension of at least one crankshaft 6 (Fig. -1) or 6' and/ or 6 (Fig. 2) drive at least one double-acting tandem air pump 34, 34'

and/or 35, 35'.

These air pumps obtain their admission air through openings 31' which correspond to the openings 31 in the engine frame (Fig. 2). The admission air is thus precompressed. This air enters through the admission valves 36 to the pump cylinders and is discharged through the discharge valves 37 and conduit 22. The cranks 38 and 39 may preferably be set at a specific angular position with respect to the cranks of the internal combustion cylinders, as will be shown later in Figures 8, 9, 10 for a specific control timing example.-

Flywheels 40, 40' and 40 respectively, are preferably arranged on the crankshaft 6 (Fig. 1) or the crankshaft 6 (Fig. 1) or the crankshaft 6. and 6 (Fig. 2,, Fig. 5) respectively. Such flywheels, as shown in Figs. 1, 2 and 5, permit a most. substantialcompensation of the tangential forces acting on all the crankshafts 6, 6 and 6 Thus there' are only small tangential forces to be compensated between the two crankshafts, by transmission through gearing 29' 29 and 30 (Fig. 2).

Fig. 6 shows schematically a top view of a gas turbine plant with a gas generator. according to this invention. The gas generator is designed here as a twin-crankshaft engine with 2X8 cylinders, 1 -1 and 1'-1''"", re-

. spectively. Thesecondary air. is fed to this engine from the twin-crank-shaft pump 33. The exhaust gases of the combustion gas generator leave the latter through four exhaust pipes 32, 32' and 32 32 respectively, which collect the exhausts from four engine cylinders each and transmit same to the gas turbine. 50. The gas turbine is equipped with a control device51, 51 shown here only schematically. Secondary air from the conduit 22 can also be delivered, through pipe 52,,directly to said control device, e.g. for overload purposes.

Fig. 7 shows -a gas turbine plant for a locomotive with direct drive. The driving wheels 59' and 59 are driven through rods 58' and 58 and through gears 57' and 57 from two gas turbines 50' and 50;. A combustion gas generator with 2X8 cylinders is again shown, with cylinders 1 -1 and 1'1"""". The eight cylinders of each bank discharge thin exhaust gases through pipes 32' and 32 respectively, to one of the two gas turbines 50' and 50 At least .one of the latter is built as a forward-turbine as well as an astern-turbine so that the locomotive can reverse its motion by a simple change of admission to the gas turbine. The gas turbines actuate the driving wheels 59' and 59 of the vehicle via gears 57 and 57 and driving rods 58' and 58 By' means of controlling devices 54 and 54 the gas admission to the turbines can be set for ahead drive or astern drive, and it may also be regulated if desired.

Fig. 7 shows, in addition, a possible arrangement for driving some auxiliaries, such as electrical generators 55, water pumps 56, etc. from the internal combustion engme.

Fig. 8, p is the pressure diagram in a cylinder of an internal combustion engine according to this invention. 1 is the corresponding temperature diagram for the air and exhaust, respectively. The upper dead center posi{ tions of the respective engine piston are marked UDC; the lower dead center positions are marked LDC.

The important points of the pressure diagram are marked a, b, c, d, e, f, g, h, i; those of the temperature diagram are marked a-i'. Lines-a-b and a'b' correspond to the admission of charging air to the cylin-' ders. Lines 12-0 and b-c represent the pressures or temperatures, respectively, during compression stroke. Lines cde and c'd'-e' refer to the combustion and expansion. 2 and e represent the pressure and temperature conditions at the start of the exhaust phase, which latter has progressed to point 1 and f at the end of the expansion stroke at .LDC. Subsequently, the exhaust gases are pushed out of the cylinder by the piston and are transmitted to the gas turbine. According to the invention, exhaust gases alone may flow to the turbine at first, and only after point g (g') the corresponding cylinder is fed with secondary air of sufi'lcient quantity to effect a relatively gradual cooling of the cylinder contents. The thus created mixture of gas and air then on ters the gas turbine, too, with decreasing (i.e. lower) temperature than the previously-exhausted unmixed gases. Therefore, less energy per weight unit of gas is transmitted to the turbine during the phase g--h. After point h (h'), a sufiicient amount of secondary air is introduced up to point i to eflfect at least near perfect" scavenging of the engine cylinder spaeewhich-is'small at UDC-from the remaining exhaust gases. This scavenging is preferably efiected by an air quantity equal.- ling several times the cylinder space to be scavenged, to accomplish also a cooling of the cylinder and piston walls as well as ofthe valves. After complete scavenging, the cylinder space is filled with relatively cold secondary air only, and with nomore exhaust gases. If the secondary air is cooled R OI to its admission to the cylinder, a relatively low temperature of the cylinder charge. can thus be obtained. After completion of the scavenging phase there maybe, according to this invention, an expansion of thealready relatively .cold cylinder charge to the lower charging pressure level, along line 1'a, With'a corresponding temperature drop illustrated byline i-=-a'. This efiects a further substantial temperature reducti on, so thatthe charging air which enters at -a.. is not, or not much, heated by the secondary air already present in the cylinder. Otherwise, the charging air weight admitted to the cylinder would be reduced, and the output of the internal combustion engine and of the gas turbine, with given process temperatures, would be smaller.

In the pressure diagram of the secondary air pump, in Fig. 9, the pressures p in one of its cylinders are shown. In order to cool and scavenge the combustion engine cylinders in the manner'illustrated in Fig. 8 and described above, the coolingand scavenging-air must be transmitted from the secondary air pump from 3 via h to i to the combustion engine cylinders with the necessary pressure. The inlet and exhaust valves of the engine cylinders must also be opened simultaneously up to the end of the scavenging period. In order to insure ob? taining the necessary pressure of the secondary air at the proper moment, the crank or. cranks of the proper secondary air pumps may be, according to this invention, so set in relation to the crank or cranks of the corresponding combustion engine pistons that the secondary airis delivered during the coolingand scavenging-period of the combustion cylinder. This is illustrated in Fig. 9 by the different setting of the engine dead centers UDC and LDC as compared to the dead center DC of the secondary air pump.

In Fig. 10, the pressure sequence p is shown in the charging air pumps whose pistons move synchronously with the combustion engine pistons, .e.g. which have simultaneousdead centerpositions with the latter. Since the secondary air pump pistons move out of phase to the combust on enginepistons, lagging behind the latter, the object of the invention has the further advantage of having charging ,air pumps start their delivery at about the moment whenthe secondary air pressure vin the engine cylinders has expanded to approximately charging air pressure level. In any case, the charging air pump is delivering air at full rate when the engine piston is moving through the middle of its stroke and. this draws in charging air. at maximum rate.

.An, operating scheme according to diagram Figures 8 to 10 may, of course, also be applied to internal combustion engines of a type different from the one illustrated in this application.

It has the great advantage of permitting the exhaust gases to enter theiturbine with high temperature, with high energy. The time interval during which the exhaust gases are cooled by the secondary air, and during whichrelatively cold secondary air enters the gas turbine as scavenging air, is relatively short. It is suitably chosen to just suflice .for good cooling and scavenging of the com u n yl ndersand t h cooling o t e s turbine.

Iclaim: I

1. Agas generator plant. built as a four-cycle supercharged internal combustion engine having a row of cylinders. in line Withinlet and outlet valves, a crankshaitior said :ITOW of cylinders, said engine delivering insecure-medium a hea n e output of e er y to a es turbine, comprising av first air compressor delivering charging air-to said cylinders, a secondary air compressor delivering secondary air .of higher pressure than that of the charging air .for cooling and scavenging said. cylinders, -a' controlzdevice. for each cylinder of said engine connected .to the inlet valveopening thereof, said control device controlling .both said-charging air andsaid secondary air, liming means for said inlet and outlet valves and said control device, an extension upon said crank-shaft for driving said secondary compressor, cranks upon said engine crank-shaft, cranks for said extensionangularly. off-set .in relation to the cranks of the Ico-roperating engine cylinders to operatively lag in phase with respect to the cranks of said co-operalting engine cylinders at such crank angle that the highest pressure of said secondary airis .created dining said cooling .and scavenging. phase.

2. A gas generator plant for delivering a pressure. medium as the sole output of energy, comprising an arrangement of a four-stroke internal combustion engine, two pistoncylinder banks having pairs of laterally adjacent cylinders with timing means, two crankshafts, a first air compressor .delivering. charging air, a secondaryair compressor delivering secondary air at a higher pressure than said charging air, control means for the supply ofcharging air and secondary air, said timing and control means for each pair of laterally adjacent cylinders being set to create synchronous working cycles therein, said control meanscomprising a control device between each pair of cylinders, one and the same control device governing the flow .of charging air and secondary air to said pair of cylinders and being actuated bylinkage operated by the same timing means which actuates the inlet and exhaust valve of said engine cylinder pairs,

extensions of the two crank-shafts of the engine driving,.

said secondary air compressor cranks for said engine-- crankshafts, cranks for said extensions for said secondary,

compressor, the cranks .of the secondary compressor on the extensions of the engine crankshafts being angularly offset in relation to the cranks of the co-operating engine;

cylinders to operatively lag in phase with respect to the cranks of said co-operating engine cylinders at such crank angle that the highest pressure of said secondary air is created during said cooling and scavenging phase.

3. A gas generator plant built as a four-cycle supercharged internal combustion engine having a row of cylinders in line with inlet and outlet valves, a cranlo, shaft for said row of cylinders, said engine delivering a pressure medium as the sole output of energy to a gas turbine, comprising a first air compressor delivering charging air to said cylinders, a secondary air compressordelivering secondary air of higher pressure than that'- of the charging air for cooling and scavenging said cylinders, a control device for each cylinder of said,

engine connected to the inlet valve opening thereof,

said control device controlling conduits for the charging,

air and the secondary air, said conduits being connected to said control device, said control device comprising a cylindrical connecting piece for said conduits to be;

connected at opposed ends thereof and having a tap-ofi. connecting to the inlet valve opening of an engine cylinder, said connecting piece comprising a movable piston sleeve to connect said conduits at predetermined periods with said tap-oil connection to said inlet valve opening, timing means for said inlet and outlet valves and said control device, an extension upon said crankshaft for driving said secondary air compressor, cranks upon said engine crank-shaft, cranks for said extension angularly off-set in relation to the cranks of the co-operating engine cylinders to operatively lag in phase with respect to the cranks of said co-operating engine cylindersat such crank angle that the highest pressure of said secondary air is created during said cooling and scavenging phase. 7

4. A gas generator plant for deliuering apressure tnediuni as the sole output of energy, comprising an arrangement of a 4-stroke internal combustion engine, two piston cylinder banks having pairs of laterally adjacent cylinders with timing means, two crankshafts, a first air compressor delivering charging air, a secondary air compressor delivering secondary air at a higher pressure than said charging air, control means for the supply of charging air and secondary air, said timing and control means for each pair of laterally adjacent cylinders being set to create synchronous working cycles therein, said control means comprising a control device between each pair of cylinders, one and the same control device governing the flow of charging air and secondary air to each pair of cylinders and being actuated by linkage operated by the same timing means which actuates the inlet and exhaust valve of said engine cylinder pairs, two conduits one for the charging air and the other for the secondary air, said conduits being connected to said control device, said control device comprising a cylindrical connecting piece, said conduits being connected at opposed ends of said connecting piece, the latter having two tap-off connections to the inlet valve openings of each pair of engine cylinders, said connecting piece comprising a movable piston sleeve to supply the air of one or the other of said conduits at predetermined periods with said tap-off connection leading to said inlet valve opening.

5. A gas generator plant built as a four-cycle supercharged internal combustion engine having a row of cylinders in line with inlet and outlet valves, a crankshaft for said row of cylinders, said engine delivering a' pressure medium as the sole output of energy to a gas turbine, comprising a first air compressor delivering charging air to said cylinders, a secondary air compressor delivering secondary air of higher pressure 'than that of the charging air for cooling and scavenging said cylinders, a control device for each cylinder of said engine connected to the inlet valve opening thereof, said control device controlling conduits for the charging air and the secondary air, said conduits being connected to said control device, said control device comprising a cylindrical connecting piece for said conduits to be connected at opposed ends thereof and having a tap-ofi connecting to the inlet valve opening of an engine cylinder, said connecting piece comprising a movable piston sleeve to connect said conduits at predetermined periods with said tap-off connection to said inlet valve opening, timing means for said inlet and outlet valves and said control device, an extension upon said crank-shaft for driving said secondary air compressor, cranks upon said engine crank-shaft, cranks for said extension angularly off-set in relation to the cranks of the co-operating engine cylinders to operatively lag in phase with respect to the cranks of said co-operating engine cylinders at such crank angle that the highest pressure of said secondary air is created during said cooling and scavenging phase, said connecting piece having a guide member secured within said connecting piece forming an annular space, the cross-sectional area of said annular space with respect to the cross-section of said piston sleeve being dimensioned so that the pressure force of the charging air and the pressure force of the secondary air upon opposed ends of said piston sleeve are made substantially equal.

6. A gas generator plant for delivering a pressure medium as the sole output of energy, comprising an arrangement of a 4-stroke internal combustion engine, two piston cylinder banks having pairs of laterally adjacent cylinders with timing means, two crankshafts, a first air compressor delivering charging air, a secondary air compressor delivering secondary air at a higher pressure than said charging air, control means for the supply of charging air and secondary air, said timing and control means for each pair of laterally adjacent cylinders being Set to'createsynchronous working cycles therein, said i0 7 control means comprising a control device between each pair of cylinders, one and the same control device governing the flow of charging air and secondary air to each pair of cylinders and being actuated by linkage operated by the same timing means which actuates the inlet and exhaust valve of said engine cylinder pairs, two conduits one for the charging air and the other for the secondary air, said conduits being connected to said control device, said control device comprising a cylindrical connecting piece, said conduits being connected at opposed ends 01 said connecting piece, the latter having two tap-01f connections to the inlet valve openings of each pair of engine cylinders, said connecting piece comprising a movable piston sleeve to supply the air of one or the other of said conduits at predetermined periods with said tapofi connection leading to said inlet valve opening, said connecting piece having a guide member secured within said connecting piece forming an annular space, the cross-sectional area of said annular space with respect to the cross-section of said piston sleeve being dimensioned so that the pressure force of the charging air and the pressure force of the secondary air upon opposed ends of said piston sleeve are made substantially equal.

7. A gas generator plant according to claim 5 wherein said control device is actuated by said timing means.

8. A gas generator plant built as a four-cycle supercharged internal combustion engine having a row of cylinders in line with inlet and outlet valves, a crank-shaft for said row of cylinders, said engine delivering a pressure medium as the sole output of energy to a gas turbine, comprising a first air compressor delivering charging air to said cylinders, a secondary air compressor delivering secondary air of higher pressure than that of the charging air for cooling and scavenging said cylinders,

a control device for each cylinder of said engine connected to the inlet valve opening thereof, said control device controlling both said charging air and said secondary air, timing means for said inlet and outlet valves and said control device, an extension upon said crank-shaft for driving said secondary air compressor, cranks upon said engine crank-shaft, cranks for said extension angularly off-set in relation to the cranks of the co-operating engine cylinders to operatively lag in phase with respect to the cranks of said co-operating engine cylinders at such crank angle that the highest pressure of said secondary air is created during said cooling and scavenging phase, said secondary air compressor being a double-act air compressor delivering secondary air at a higher pres-' sure than said charging air, control means for the supply of charging air and secondary air, said timing and control means for each pair of laterally adjacent cylinders being set to create synchronous working cycles therein,

said control means comprising a control device between each pair of cylinders, one and the same control device governing the flow of charging air and secondary air to said pair of cylinders and being actuated by linkage operated by the same timing means which actuates the inlet and exhaust valve of said engine cylinder pairs, extensions of the two crank-shafts of the engine driving, said.

secondary air compressor cranks for said engine crankshafts, cranks for said extensions for saidsecondary com pressor, the cranks of the secondary compressor on the extensions of the engine crankshafts being angularly offset in relation to the cranks of the co-operating engine cylinders to operatively lag in phase with respect toth'e, cranks ofsaid co-operating engine cylinders at such crank angle that the highest pressure of said secondary air is created during said cooling and scavenging phase, said secondary air compressor being a double-acting air piston compressor connected at its suction side directly'to an air receiver for the charging air formed by the walls of the engine frame. 7

10. A gas generator plant built as a four-cycle super? charged internal combustion engine having a row of cyl inders in line with inlet and outlet valves, a crankshaft for said row of cylinders, said engine delivering a pressure medium as the sole output of energy to a gas turbine, comprising a first air compressor delivering charging air to said cylinders, 21 secondary air compressor delivering secondary air of higher pressure than that of the charging air for cooling and scavenging said cylinders, a control device for each cylinder of said engine connected to the inlet valve opening thereof, said control device controlling conduits, for the charging air and. the secondary air, said conduits being connected to said control device, said control device'comprising a cylindrical connecting piece for said conduits to be connected at opposed ends thereof and having a tap-ofinconnecting to the inlet valve opening of an engine cylinder, said con-. necting piece comprising a movable piston sleeve to connect said conduits at predetermined periods with said tap-off connection to said inlet valve opening, timing means for said inlet and outlet valves and said control device, an extension upon said crankshaft for driving said secondary air compressor, cranks upon said engine crank-shaft, cranks for said extension angularly ofi-set in relation to the cranks of the co-operating engine cylinders to operatively lag in phase with respect to the cranks of said co-operating engine cylinders at such crank angle that the highest pressure of said secondary air is created during said cooling and scavenging phase, said secondary air compressor being a double-acting air piston compressor connected at its suction side directly to.

an air receiver for the charging air formed by the walls of the engine frame.

11. A gas generator plant for delivering a pressure medium as the sole output oftenergy, comprising an arrangement of a 4-stroke internal combustion engine, two piston cylinder banks having pairs of laterally adjacent cylinders with timing means, two crankshafts, a first air" compressor delivering charging air, a secondary air compressor delivering secondary air at a higher pressure than said charging air, control means for the supply of charging air and secondary air, said timing and control means for each pair of laterally adjacent cylinders being set to create synchronous working cycles therein, said control means comprising a control device between each pair of cylinders, one and the same control device governing the flow of charging air and secondary air to each pair of cylinders and being actuated by linkage operated by the same timing means which actuates the inlet andexhaust valve of said engine cylinder pairs, two conduits one for the charging air and the other for the secondary air, said conduits being connected to said control device, said control device comprising a cylindrical connecting piece,-

said conduits being connected at opposed ends of said connecting piece, the latter having two tap-01f connectionsto the inlet valve openings of each pair of engine cylinders, said connecting piece comprising a movable piston sleeve to supply the air of one or the other of said conduits at predetermined periods with said tap-02f connection leading to said inlet valve opening, said secondary air compressor being a double-acting air piston compressor connected at its suction side directly to an air receiver for the charging air formed by the walls of i the engine frame.

12. A gas generator plant built as a four-cycle super-- charged internal combustion engine having a row of cylindcrs 'in line with inlet and outlet valves, a crank-shaft, for said row of cylinders, said engine delivering a pressure medium as thesole output of energy to a gas tur: bine, comprising a first air compressor delivering char'g ing air to said cylinders, a secondary air compressor delivering secondary air of higher pressure than that of the charging air for cooling andtscavenging said cylinders, a control device for each cylinderof said engine connected to the inlet valve opening thereof, said control device controlling conduits for the charging air and the secondary air, said conduits being connected to said control device, said control vdevice comprising a cylindrical connecting piece for said conduits to be connected at opposed ends thereof and having a tap-off connecting to the inlet valve opening of an engine cylinder, said connecting piece comprising a movable piston sleeve to connect said conduits at predetermined periods with said tap-oft connection to said inlet valve opening, timing means for said inlet and outlet valves and said control device, an extension upon said crankshaft for driving said secondary air compressor, cranks upon said engine crankshaft, cranks for said extension angularly oii-set in relation to the cranks of the co-operating engine cylinders to operatively lag in phase with respect to the cranks of said co-operating engine cylinders at such crank angle that the highest pressure of said secondary air is created during said cooling and scavenging phase, said connecting piece having a guide member secured within said con necting piece forming an annular space, the cross-sectional area of said annular spacewith respect to the cross-section of said piston sleeve being dimensioned so that the pressure force of the charging air and the pressure force of the secondary air upon opposed ends of said piston sleeve are made substantially equal, said secondaryair compressor being a double-acting air piston compressor connected at its suction side directly to an air receiver for the charging air formed by the walls of the engine frame.

'13. A gas generator plant for delivering a pressuremedium as the sole output of energy, comprising an arrangement of a 4-stroke internal combustion engine, two

piston cylinder banks having pairs of laterally adjacent cylinders with timing means, two cranks'hafts, a first air compressor delivering charging air, a secondary air compressor delivering secondary air at a higher pressure than said charging air, control means for the supply of charging air and secondary air, said timing and control means for each pair of laterally adjacent cylinders being set to create synchronous working cycles therein, said control connecting piece, the latter having two tap-oii connections to the inlet valve openings of eachypair of engine cylinders, said connecting piece comprising a movable piston sleeve to supply the air of one or the other of said conduits at predetermined periods with said tap-off connection leading to said inlet valve opening, said connecting piece having a guide member secured within said con-- necting. piece forming an annular space, the cross-sectienal area of said annular space with respectto the cross-section of said piston sleeve being dimensioned so, that the pressure force of the charging air and .the pres sure force of the secondary air upon opposed endsof said piston sleeve are made substantially equal, said secondary air compressor being a double-acting air piston compres-' sor connected at its suction side directly to an air receiver for the charging air formed by the walls of the engine frame.

14. A gas generator plant for delivering a pressure;

medium as the sole output of energy, comprising an arrangement of a 4-stroke internal combustion engine, two piston cylinder banks having pairs of laterally adjacent cylinders with timing means, two crankshafts, a first air compressor delivering charging air, a secondary air compressor delivering secondary air at a higher pressure than said charging air, control means for the supply of charging air and secondary air, said timing and control means for each pair of laterally adjacent cylinders being set to create synchronous working cycles therein, said control means comprising a control device between each pair of cylinders, one and the same control device governing the flow of charging air and secondary air to each pair of cylinders and being actuated by linkage operated by the same timing means which actuates the inlet and exhaust valve of said engine cylinder pairs.

15. A gas generator plant for delivering a pressure medium as the sole output of energy, comprising an arrangement of a 4-stroke internal combustion engine, two piston cylinder banks having pairs of laterally adjacent cylinders with timing means, two crankshafts, a first air compressor delivering charging air, a secondary air compressor delivering secondary air at a higher pressure than said charging air, control means for the supply of charging air and secondary air, said timing and control means for each pair of laterally adjacent cylinders being set to creat synchronous working cycles therein, said control means comprising a control device between each pair of cylinders, one and the same control device governing the fiow of charging air and secondary air to each pair of cylinders and being actuated by linkage operated by the same timing means which actuates the inlet and exhaust valve of said engine cylinder pairs, said secondary air compressor being a double-acting air piston compressor connected at its suction side directly to an air receiver for the charging air formed by the walls of the engine frame.

16. A gas generator plant for delivering a pressure medium as the sole output of energy, comprising an arrangement of a 4-stroke internal combustion engine, two piston cylinder banks having pairs of laterally adjacent cylinders with timing means, two crankshafts, a first air compressor delivering secondary air at a higher pressure than said charging air, control means for the supply of charging air and secondary air, said timing and control means for each pair of laterally adjacent cylinders being set to create synchronous working cycles therein, said control means comprising a control device between each pair of cylinders, one and the same control device governing the flow of charging air and secondary air to each pair of cylinders and being actuated by linkage operated by the same timing means which actuates the inlet and exhaust valve of said engine cylinder pairs, and a valve for two cylinders arranged side-by-side in an approximately transverse plane to the engine shaft, said valve governing the flow of charging air and of secondary air to said engine cylinders.

17. A gas generator plant for delivering a pressure medium as the sole output of energy, comprising an arrangement of a 4-stroke internal combustion engine, two piston cylinder banks having pairs of laterally adjacent cylinders with timing means, two crankshafts, a first air compressor delivering charging air, a secondary air compressor delivering secondary air at a higher pressure than said charging air, control means for the supply of charging air and secondary air, said timing and control means for each pair of laterally adjacent cylinders being set to create synchronous working cycles therein, said control means comprising a control device between each pair of cylinders, one and the same control device governing the flow of charging air and secondary air to each pair of cylinders and being actuated by linkage op erated by the same timing means which actuates the inlet and exhaust valve of said engine cylinder pairs, ducts common for said banks for the admission of charging and secondary air arranged along the middle between the same, and separate conduits outside of the combustion engine cylinders for the discharge of exhaust gases.

18. A supercharged four-stroke cycle internal combustion engine gas generator according to claim 14 wherein a secondary air compressor is arranged at each end of the combustion engine, and both compressors deliver to one receiver of the combustion engine.

References Cited in the file of this patent UNITED STATES PATENTS 759,093 Gardner May 3, 1904 1,436,434 Conners Nov. 21, 1922 1,620,565 McKeoWn Mar. 8, 1927 1,741,730 Newton Dec. 31, 1929 2,117,700 Burkhardt May 17, 1938 2,155,068 Walti Apr. 18, 1939 2,283,606 Lewis May 19, 1942 

